Update of /home/cvsd/slony1/slony1-engine/src/slon
In directory main.slony.info:/tmp/cvs-serv8627/src/slon

Modified Files:
	sync_thread.c 
Log Message:
Reduce the quantity of spurious events generated:

1.  generate_sync_event() only needs to generate a SYNC on a node
    that is the origin for a set

2.  sync thread generates a SYNC when it starts; in later iterations,
    it will only generate a SYNC for its node if that node is the origin
    for a replication set

Per discussions with Jan Wieck on 2007-02-09; this seemed an experiment
worth trying.  I tried it, and the tests run fine, so I'm committing this.


Index: sync_thread.c
===================================================================
RCS file: /home/cvsd/slony1/slony1-engine/src/slon/sync_thread.c,v
retrieving revision 1.18
retrieving revision 1.19
diff -C2 -d -r1.18 -r1.19
*** sync_thread.c	27 Oct 2006 20:10:57 -0000	1.18
--- sync_thread.c	14 Mar 2007 15:59:32 -0000	1.19
***************
*** 47,53 ****
--- 47,55 ----
  	SlonDString query1;
  	SlonDString query2;
+ 	SlonDString query3;
  	PGconn	   *dbconn;
  	PGresult   *res;
  	int			timeout_count;
+ 	bool first_time = TRUE;
  
  	slon_log(SLON_DEBUG1,
***************
*** 84,89 ****
  	dstring_init(&query2);
  	slon_mkquery(&query2,
! 				 "select %s.createEvent('_%s', 'SYNC', NULL);",
! 				 rtcfg_namespace, rtcfg_cluster_name);
  
  	timeout_count = (sync_interval_timeout == 0) ? 0 :
--- 86,99 ----
  	dstring_init(&query2);
  	slon_mkquery(&query2,
! 		     "select %s.createEvent('_%s', 'SYNC', NULL)"
! 		     " from %s.sl_node where no_id = %s.getLocalNodeId('_%s') "
! 		     " and exists (select 1 from %s.sl_set where set_origin= no_id);",
! 		     rtcfg_namespace, rtcfg_cluster_name,
! 		     rtcfg_namespace, rtcfg_namespace, rtcfg_cluster_name, rtcfg_namespace);
! 
! 	dstring_init(&query3);
! 	slon_mkquery(&query3,
! 		     "select %s.createEvent('_%s', 'SYNC', NULL);",
! 		     rtcfg_namespace, rtcfg_cluster_name);
  
  	timeout_count = (sync_interval_timeout == 0) ? 0 :
***************
*** 123,140 ****
  
  			PQclear(res);
! 			res = PQexec(dbconn, dstring_data(&query2));
  			if (PQresultStatus(res) != PGRES_TUPLES_OK)
  			{
  				slon_log(SLON_FATAL,
  						 "syncThread: \"%s\" - %s",
! 						 dstring_data(&query2), PQresultErrorMessage(res));
  				PQclear(res);
  				slon_retry();
  				break;
  			}
! 			slon_log(SLON_DEBUG2,
  					 "syncThread: new sl_action_seq %s - SYNC %s\n",
  					 last_actseq_buf, PQgetvalue(res, 0, 0));
  			PQclear(res);
  
  			/*
--- 133,153 ----
  
  			PQclear(res);
! 			res = PQexec(dbconn, dstring_data(first_time? &query3:&query2));
  			if (PQresultStatus(res) != PGRES_TUPLES_OK)
  			{
  				slon_log(SLON_FATAL,
  						 "syncThread: \"%s\" - %s",
! 					 dstring_data(first_time?&query3:&query2), PQresultErrorMessage(res));
  				PQclear(res);
  				slon_retry();
  				break;
  			}
! 			if (first_time) {
! 				slon_log(SLON_DEBUG2,
  					 "syncThread: new sl_action_seq %s - SYNC %s\n",
  					 last_actseq_buf, PQgetvalue(res, 0, 0));
+ 			}
  			PQclear(res);
+ 			first_time = FALSE;
  
  			/*
***************
*** 179,182 ****
--- 192,196 ----
  	dstring_free(&query1);
  	dstring_free(&query2);
+ 	dstring_free(&query3);
  	slon_disconnectdb(conn);